hi can u help me with this please

 

-which one of these is the atom= 2,8,8,2?

-for neutral atoms with 21-30 protons, the third shell resumes filling;that is, for element 21, the element arrangement is 2,8,9,2.

-a-write down how the electrons are arranged in an atom containing 30 electrons???

-b- how are the electrons arranged in a neutral atom containing 31 protons?

 

thankyou in advance for all ur help. jane (:

hi can u help me with this please

 

-which one of these is the atom= 2,8,8,2?

-for neutral atoms with 21-30 protons, the third shell resumes filling;that is, for element 21, the element arrangement is 2,8,9,2.

-a-write down how the electrons are arranged in an atom containing 30 electrons???

-b- how are the electrons arranged in a neutral atom containing 31 protons?

 

thankyou in advance for all ur help. jane (:

 

The thing that you need to look for in your text book or simply google it is " Electronic Configuration". This is the most common topic among chemistry book where you have to give the electronic configuration or else guess what element or ion has a particular EC.

 

I will give answer to your first question but forgive me the forums rules don allow me to help you completely unless I or anyother member sees that you have tried to solve the problem and have not merely asked them!.

 

2,8,8,2 means that there are 2 electron in the first shell followed by 8 in the second and again 8 in the third and then 2 in the fourth and last shell. Remember the valence electron (the no of electrons in the last shell) should direct you to the group from which the element is. For example, in the element has 2 electrons in the final shell so it must be from he 2nd group and adding the number of electron up makes 2+8+8+2 = 20. In a neutral atom, no of electron are similar to no of proton so look in the periodic table and Ca should have this electronic configuration.

thanx for ur help :]

ince you're smart enough to come here for information I'll give you some more. The shells are just the beginning. As you study chemistry further you'll discover there are also subshells within the shells and orbitals within the subshells. it gets quite complex, but very very interesting :0) careful when you google the subject, because it will often result in stuff beyond the level of your current course